Oscillation device



Nov. 1, 1932. L. J. LE'SH 1,885,118

OSCILLATION DEVICE Filed May 11,- 1928 Imrsn nr' Laurence 11L ssh 7 .putcircuit of the tube to the winding of the.

Patented Nov. 1', 1932 UNITED sures 1,s ss-,118

PATENT ol-"Ficr.

LAURENCE J. 15188, 01' CHICAGO, 'ILLDTOIB, ABGIGNOB, BY m1! ASSIGNMENTS,'10

ASSOGIA'I'ED ELECTRIC LABORATORIES, INC, 01 CHICAGO, ILLINOIS, ACOBPORA- TIOH' OI DELAWARE oscmm'rron nnvrcn Application fled Kay 11,1am. Serial no. ammo.

My invention relates to an improvement in oscillation devices. The mainob ect of my invention is the design of a device to produce oscillationsof predetermined frequencits which can be readily controlled.

The device comprises a relay operating in conjunction with athree-element electron tube. The relay is of special design, which Ihave termed a tuned mlcrophonic contact relay. This relay is providedwith a magnet and a tuned reed armature upon which is mounted amicrophone so sitioned as not to interfere'with the natura period ofvibration of the reed but at the same time re-produce the vibrations setup by1 the reed.

. The action of the microp one causes variations corresponding to thevibrations of the reed to occur in the grid or input circuit of theelectron tube. Amplified circuits from the tube are transmitted from theplate or anode circuit to the winding of the magnet.

This feed-back arrangement from the outmagnet causes oscillations to beset up in the circuits which. correspond to the frequencies to which thereed is tuned or adjusted.

As the reed itself is the controlling factor as to the frequency of theoscillations, it 15 only necessary to provide a reed whlch w1ll vibrateto the frequency desired inorder to produce oscillations correspondingto that frequency.

llhe microphone may be of any well known type such as illustrated anddescribed in Patent No. 1,324,357, granted to H. A. Laree, December 9,1919. The cup'containing the granular carbon,v as disclosed in thepatent, is or the type which is mounted upon the reed armature.

lt ly invention is illustrated in theaccompanying drawing, wherein Fi 1shows a plan view of the tuned microp onic contact relay with circuitco-operating with an electron tuloe.

.l ig. 2 is a side view of the relay.

' Referring to the figures, it will be noted that the relay comprisestwo magnet windings 8 and 9 mounted upon a metal base 1. This base isprovided with .9. lug or extension 2 throughwhich pass two adjustingnuts 3 and 5 and the screws 4 and 6 for holding or positioning themagnets 8 and 9. The base 1 is also provided with the extension or lug11 upon which is mounted a tuned reed 10, by

a. means of the three screws 29. This reed ex- 22 threaded therein andpositioned or locked by means of. the nuts 23 and 24. The lug orextension 13 forming a part of the base 1 supports a contact springmounted thereon and insulated therefrom by the insulating washers 16. Ascrew 14 passes through the washers and the lug 13 and is held in placeby the lock nut 18. The contact spring 15 extends to the cup 21 and isattached thereto by means of the nut upon the threaded projection 19which passes through an opening in the spring 15.

A setof terminals 26, 27, and 28 are mounted upon the base 1 by means ofthe screw and insulated from one another by means of the insulatingwashers 40, as shown in Fig. 2.

The terminal 28 is, however, in contact with base 1.

The electron tube 40 comprises the cathode 41. grid 42, and anode 43.

@The winding of the magnets 8 and 9 are in series and are connected tothe terminals 26 and 27. These terminals are connected to the anode 43-and the battery 46 in series with winding 49 of transformer R, formingthe output circuit of the tube 40. The terminals of the microphone 21areconnec'ted respectively to terminals 17 and 28.. These terminals inturn are connected to battery 47 and the winding 44 of transformer T,and to the grid 42 through winding of T. The filament or cathode 41 issupplied by a source of battery 48 in the usual manner.

s From the foregoing, it will be noted that the microphone 21 isincluded in the grid circuit of the tube 40, transformer T and thewindings of the magnets 8 and 9 are included in the anode or outputcircuit of the tube 40 in series with winding49 of the transformer R.

As the output circuit is fed back into the windings of magnets 8 and 9and these magnets control the operation of the microphone 21 by meens ofthe tuned reed 10, oscillations will be set up in the circuitcorresponding to the frequency of the vibrations set up in the reed 10.V

The enode circuit includes the winding 49 of the transformer R, andconsequently the is current is induced in the winding 50 01 thetransformer which is connected to the output circuit ieeds i and 52.

These leads may extend to devices which are tuned to respond to thetransmitted osciiistions.

is ciairned is:

i. in an oscillating device, the combination oi an electron tube savinga cathode, grid,

and anode, en eiectro-rnegnet provided with 29 e, tuned egnetic reedhaving e :zzicrophone mounted thereon, an input trensi'oriner and cutputtransformer, eiectricei circuit iding anode, of said e primary Windingof said output tran former, electrical circuit winding the micro; :1G11e,a source of current and the priwin of said inpifi transformer, andslice circuit inciuning the secondary said input transformer and the Mgrid of said tube.

, in oscillating device, the combineo s cuss plate having at magnet anda ed mounted thereon, a two element micropnone having one eieinentsupported by said reed, a spring mounted on said base piste andsupporting the other eienient of said microphone, a circuit including asource oi current, said; tuned reed, said microphone, and saidsupporting spring, and an amplifier 4c hevingnn input circuit coupled tosaid first circuit and an output circuit inciuding said magnet.

3. In combination, a magnet having a tuned reed armature, a two elementmicropiionev having one element anchored to said armsture, e springsupporting the other element of said microphone, a circuit including a.source of current, said armature, microphone and spring, and the primarywinding of a transformer, and an amplifier-having a grid circuitincluding the secondary winding of said transformer and a plate circuitincluding said ma et.

witness whereof, I hereunto subscribe my name this 8th day of May, A. D.1928.

LAURENCE J. LESH.

